Secretion of extracellular polymeric substances (EPS) is essential to biofilm formation. The substances (including polysaccharides, extracellular DNA and proteins) in EPS play distinct roles and are closely related to the development of biofilms. However, methods that can be used to in situ characterize the properties or the function of EPS are rather limited, which results in the current studies of EPS is insufficient to uncover the underlying mechanism that determines biofilms formation. Here, by using a combination of molecular microbiology, microfluidic and multiple state-of-the-art microscopical techniques, we in situ investigated the properties and functions of EPS during biofilms formation, including that 1) mapping the height of the attaching bacterial surface; in situ characterization of the microrheology in EPS; quantitatively measurement of the adhesion or friction force between the bacterium and the surface; 2) in situ monitoring of the secretion of EPS.
Properties and functions of extracellular polymeric substances